What is BMI?

BMI stands for Body Mass Index. This is a standard for measuring weight against height. This method, however, does not measure the fat versus muscle in the body. Body Mass Index only measures weight and height.

Have you heard the term BMI before? What about Body Mass Index? These have both been used in many diet plans and workout regimens. You may have even heard about this mentioned by your doctor. Even certain jobs require a specific BMI, such as the U.S. military. 

There are many good things about the Body Mass Index regarding weight gain or weight loss. This index can be used to measure a healthy weight. There are limitations to the Body Mass Index, though. The fact that the Body Mass Index doesn’t measure fat and muscle can lead to results that aren’t entirely accurate. This article will precisely examine BMI and all its benefits and limitations. How helpful is the Body Mass Index? Let’s talk about it.

How Does the Body Mass Index Work?

The Body Mass Index measures your weight against your height and works by dividing your weight by your height. Based on the result of this measurement, you will be put into one of four categories. These categories are obesity, overweight, healthy weight, or underweight. The Body Mass Index is one of the easiest ways to determine someone’s weight category. While there are limitations to the fact that it doesn’t measure your body fat, this index has been very useful for helping in diagnosing health issues regarding weight. Once a BMI in an unhealthy range is determined, health providers may do further testing to determine the cause. The Body Mass Index is known to be a reliable source of information when it comes to deciding whether someone has a high or low amount of body fat. Even without measuring exactly how much body fat a person has, this index system works for most people. 

How Exactly is BMI Calculated?

The BMI can be calculated in both the metric and standard systems. In the metric system, you can determine BMI by dividing the weight in kilograms by the height in meters. This will give you your BMI score. For the stander system, weight in pounds is divided by height in inches squared and also multiplied by a conversion factor of 703. This will also give you the same score. You can use either method. If you prefer the metric method, you can easily convert your weight in pounds to kilograms and your height in inches into meters.

Healthy and Unhealthy Body Mass Index Ranges

The Body Mass Index has four ranges that determine if you are at a healthy weight for your height. Numbers below 18.5 are in the underweight category. Numbers that are between 18.5 and 24.9 are in the healthy range. From 25 to 29.9, one would be classified as overweight, and anything above 30 is obese.

Body Mass Index for Children and Teenagers

Using the BMI systems for children and teenagers has become more common over the years due to the increase in childhood obesity. In the United States, many public k-12 schools educate the students on the Body Mass Index in classes such as a health class. For those under 18, BMI is determined both through age and gender factors. BMI for children and teens is also helpful for those who are underweight. Determining an unhealthily low BMI may help children and teenagers be diagnosed earlier for potential issues that may be causing them to be at a low weight. 

Alternative Methods for Determining Body Fat

A few other methods can be used to determine someone’s body fat and are more likely to be used for those that the Body Mass Index doesn’t work as well for. One method is called underwater weighing, which is a better indicator of fat compared to muscle. This method can be expensive. Another way is to measure skinfold thickness, and this is used with calipers can be an uncomfortable way of determining body fat. The Body Mass Index works so well because it makes sense for most people, is cheap or even free to do on your own, and is very easy and non-invasive.  

Limitations of the Body Mass Index

The Body Mass Index does have some limitations. For example, a person with a large muscle mass would likely be put in an unhealthy BMI category. This is because muscle weighs a bit more than fat. Most bodybuilders have very little fat compared to their muscle mass. People who train for this professionally would be mostly put in the overweight or obese category because of their weight versus their height. This is why the Body Mass Index isn’t perfect. It cannot determine the exact amount of body fat compared to muscle. However, most professionals understand this issue, and BMI is now usually only applied to individuals who are deemed to not have more than the typical amount of muscles. The public needs to understand this limitation when using the Body Mass Index to determine their category. 

Final Thoughts

Although the BMI system has some limitations to its use, it is a primarily reliable way of determining body fat. The Body Mass Index is not the final say on how much body fat one person has or the reasons behind that. This system is used as a screening tool. Once it is decided that someone’s BMI is outside the healthy range, their medical professionals will be able to perform further screenings and testing to find out why that particular person does not have a healthy BMI.

BMI is calculated with a very simple formula that even non-professionals may be able to determine on their own. This makes this system much more accessible for those who are concerned about their weight. Whenever someone is found to be outside of a healthy range through these calculations, they can take steps with medical providers to work toward being healthier. BMI can also be used for children and teenagers specifically to combat childhood obesity early on. Most alternative methods for testing body fat mass are more expensive and less accessible to the general public. However, due to the limitations of BMI, these other methods may be used to determine actual body fat in individuals that require these screenings.